Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2

[pavan.tulasi]

For my tool I need to locate all of my database list on once JFrame and I succeeded to handle them individually.
And I want to reduce the code and used for loop replacing duplicate code for all databases required.

the code is below. Please check and advise why I am getting the mentioned error.

import javax.swing.*;

import java.sql.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.border.*;
import java.io.*;
public class OurTool extends JFrame implements MouseListener
{
public static void main(String args[])
{
OurTool f=new OurTool();
f.setSize(2000,1000);
f.setResizable(false);
f.setVisible(true);


f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent w)
{
System.exit(0);
}
});
}
JButton[] dbBut= new JButton[2];
String dbList[] = {"DB1","DB2"};
int dbIndex,butTop;

public OurTool()
{
Container Con = getContentPane();
Con.setLayout(null);

for (dbIndex=1,butTop=10;dbIndex<=2;dbIndex++,butTop+= 105)
{
dbBut[dbIndex]= new JButton(dbList[dbIndex]);
Con.add(dbBut[dbIndex]);
dbBut[dbIndex].setSize(200,100);
dbBut[dbIndex].setBounds(5,butTop,200,100);
dbBut[dbIndex].addMouseListener(this);
}

}

public void mousePressed(MouseEvent ME)
{
}

public void mouseClicked(MouseEvent ME)
{
JButton B1=(JButton) ME.getSource();

for (dbIndex=1;dbIndex<=2;dbIndex++)
{
if (B1==(JButton) dbBut[dbIndex])
{
try
{
connectToMyDB(dbList[dbIndex]);
}catch(SQLException e){}
catch(ClassNotFoundException e){}
}
}
}
public void mouseReleased(MouseEvent ME)
{

}
public void mouseExited(MouseEvent ME)
{

}
public void mouseEntered(MouseEvent ME)
{

}
public void connectToMyDB(String mydb) throws ClassNotFoundException,SQLException
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cn=DriverManager.getConnection("jdbcdbc:mydb","user1","pwd1");
System.out.println("connected to database..");
Statement st=cn.createStatement();
ResultSet rs=st.executeQuery("select * from tab1;");
while(rs.next())
{
System.out.println(rs.getString("Time")+" "+rs.getString("Message"));
}

rs.close();
st.close();
cn.close();
}
}

--- Update ---

I changed JButton declaration and am out of ArrayIndexOutOfBoundException now..and got "NullPointerException" now.

new code is:

import javax.swing.*;

import java.sql.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.border.*;
import java.io.*;
public class OurTool extends JFrame implements MouseListener
{
public static void main(String args[])
{
OurTool f=new OurTool();
f.setSize(2000,1000);
f.setResizable(false);
f.setVisible(true);


f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent w)
{
System.exit(0);
}
});
}
JButton dbBut[];
String dbList[] = {"DB1","DB2"};
int dbIndex,butTop;

public OurTool()
{
Container Con = getContentPane();
Con.setLayout(null);

for (dbIndex=1,butTop=10;dbIndex<=2;dbIndex++,butTop+= 105)
{
dbBut[dbIndex]= new JButton(dbList[dbIndex]);
Con.add(dbBut[dbIndex]);
dbBut[dbIndex].setSize(200,100);
dbBut[dbIndex].setBounds(5,butTop,200,100);
dbBut[dbIndex].addMouseListener(this);
}

}

public void mousePressed(MouseEvent ME)
{
}

public void mouseClicked(MouseEvent ME)
{
JButton B1=(JButton) ME.getSource();

for (dbIndex=1;dbIndex<=2;dbIndex++)
{
if (B1==(JButton) dbBut[dbIndex])
{
try
{
connectToMyDB(dbList[dbIndex]);
}catch(SQLException e){}
catch(ClassNotFoundException e){}
}
}
}
public void mouseReleased(MouseEvent ME)
{

}
public void mouseExited(MouseEvent ME)
{

}
public void mouseEntered(MouseEvent ME)
{

}
public void connectToMyDB(String recDB) throws ClassNotFoundException,SQLException
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cn=DriverManager.getConnection("jdbcdbc:mydb","user1","pwd1");
System.out.println("connected to database..");
Statement st=cn.createStatement();
ResultSet rs=st.executeQuery("select * from tab1;");
while(rs.next())
{
System.out.println(rs.getString("Time")+" "+rs.getString("Message"));
}

rs.close();
st.close();
cn.close();
}
}

[AlexHail]

Hi. Please put your code in code tags next time.

Search your code for loose values and null. Any value that isn't preset/determined is at hazard for an NPE. I would suggest trying the good old..

try {
} catch (Exception e) {
    System.out.println("e");
}

When you stop getting tons of errors and your exception is printed out, you might be that much closer to finding your null value

--- Update ---

Hi. Please put your code in code tags next time.

Search your code for loose values and null. Any value that isn't preset/determined is at hazard for an NPE. I would suggest trying the good old..

try {
// whatever
} catch (Exception e) {
    System.out.println("e");
}

When you stop getting tons of errors and your exception is printed out, you might be that much closer to finding your null value

[jps]

Hi pavan, in the first posted example, the array is declared with: JButton[] dbBut= new JButton[2];
This gives the array two(2) slots, numbered 0 and 1. Then in the loop: for (dbIndex=1,butTop=10;dbIndex<=2;dbIndex++,butTop+= 105)
This loop will run for <=2, which is 0, 1, and 2. There is no third slot in the array with index number 2. This off-by-one-error is common and understanding the concept of index numbering is necessary.

In the second posted sample the array is not initialized as it was in the first example, remember: JButton[] dbBut= new JButton[2];

Browse this tutorial for details, but do try to understand why both examples failed.